This invention relates to a road gully or inspection cover assembly, and more particularly to such an assembly that permits ready adjustment of the vertical position of the cover of the assembly.
It is a necessary part of the construction of new roads to incorporate water gullies and manholes therein all of which have to be covered, the covers eventually needing to be at the finished level of the road.
Common practice is initially to construct a road to a base course level and thereafter to apply a wearing course of substantial thickness to complete the road.
The gullies and manholes are incorporated prior to application of the wearing course, and invariably extend above the base course with their covers located at a level anticipating that of the final wearing course.
There is often a considerable period of time, particularly in new housing estates, between laying of base courses and wearing courses, and this can create a number of problems.
As the covers project above the surface of the base course by the thickness of the wearing course, they constitute serious obstacles to vehicles with low clearance as well as to pedestrians. They can cause damage to, and can themselves be damaged by, vehicles, particularly road cleaning vehicles incorporating mechanical front shovels. In such situations, the assemblies, or at least the covers thereof, often have to be replaced and the associated manhole or gully cleared of rubble to prevent blockage.
Additionally, the finished level of the water gullies, being above that of the base course prior to the application of the wearing course, results in the accumulation of large pools of water on the roads during wet weather.
It has been proposed, for example in my European patent no. 0715028, to provide a road gully or inspection cover assembly the position of the cover of which can be adjusted to accommodate the difference in levels between the base course and the wearing course of the road.
More particularly, the known assembly comprises a fixed outer frame and an adjustable inner frame slidably supported in the outer frame and capable of being located at any position between a lowermost position and an uppermost position, the inner frame supporting the cover of the assembly whereby the cover can initially be located at the base course level of the road, and subsequently raised and located at the wearing course level of the road.
Such an assembly is suitable for situations in which the depth of the wearing course is within certain defined limits whereby strict regulations relating to the extent of overlap of the components of the assembly can be satisfied.
In particular, it is necessary to provide a minimum 50 mm vertical overlap of the cover with its supporting frame, and a minimum 50 mm overlap between the inner and outer frames.
The standard depth of the outer frame is 100 mm, the thickness of the base plate of the outer frame is 6 mm, and the recommended thickness of the wearing course is 40 mm. The overall relationship between the inner and outer frames of this known assembly is such as to provide a maximum adjustability between the lowermost and uppermost positions of the inner frame, and therefore the maximum depth of wearing course that can be accommodated by the assembly, of 44 mm.
It would be desirable to be able to provide a road gully or inspection cover assembly capable of accommodating thicker wearing courses than heretofore, whilst still satisfying British Standard regulations.
According to the present invention there is provided a road gully or inspection cover assembly comprising an outer frame having an upstanding outer wall and integrally formed support means extending inwardly of the lower regions of the outer wall over part at least of the peripheral extent of said outer wall, a first temporary inner frame for location within the outer frame, the outer frame and the first temporary inner frame co-operating to support a cover for the assembly in a first, lowermost position associated with the base course level of the road, and a second inner frame which, on removal of the first inner frame from within the outer frame, can be located within the outer frame to support the cover at a higher position associated with the wearing course level of the road.
There may be a plurality of second inner frames, one associated with each of a number of different higher positions.
Alternatively, the position of the second inner frame relative to the outer frame may be vertically adjustable, for example by providing selectively variable support means reacting between the outer frame and the underside of the second inner frame.
In a first embodiment of the invention, the outer frame is of upwardly-open channel shape in transverse section over said part at least of the peripheral extent of the outer wall thereof, the inner wall of the section comprising said support means, the lowermost position of the cover being determined by abutment of the cover with the inner wall of the channel section, the first temporary inner frame surrounding the cover in its lowermost position to close the hollow interior of the outer frame, the second inner frame being received within the channel section of the outer frame to determine the higher position of the cover.
In a second embodiment of the invention, the outer frame is of substantially L-shape in transverse section over said part at least of the peripheral extent of the outer wall thereof, the inwardly extending lower leg of the section comprising support means having a horizontal upper surface thereto.
The lowermost position of the cover may be determined by abutment of the cover with the upper surface of the support means, the first temporary inner frame also seating on the upper surface of the support means to surround the cover in its lowermost position and to close the outer frame, the second inner frame seating on the upper surface of the support means to determine the higher position of the cover.
Alternatively, the first temporary frame may seat on the upper surface of the support means and may be configured to receive thereon the cover, typically a gully grate, to determine the lowermost position of the cover, the second inner frame again seating on the upper surface of the support means to determine the higher position of the cover.
The invention is particularly suited to assemblies incorporating covers of generally rectangular shape, it being preferred that the inwardly extending support means are provided at the corner regions only of the outer frame.
Accordingly the first and second inner frames will include downwardly extending leg portions at the corner regions thereof adapted to seat on, and co-operate with, the support means on the outer frame, the extents of the first and second inner frames between the corner regions being of lesser depth than the corner regions.
Conveniently the outer frame and the second inner frame include adjustable attachment means operable to effect a connection between the sidewalls thereof once the inner frame is located at a desired level relative to the outer frame, for example one or more vertical slots in one of the frames and a locking bolt on the other frame.